#define _CRT_SECURE_NO_WARNINGS 1
#include <cmath>
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include<math.h>
#include<stdlib.h>
#include<stdio.h>
using namespace std;

class Solution {
public:
    int peakIndexInMountainArray(vector<int>& arr) {
        int left = 0;
        int right = arr.size() - 1;
        while (left < right)
        {
            int mid = left + (right - left) / 2;
            if (arr[mid] < arr[mid + 1]) left = mid + 1;
            else if (arr[mid] > arr[mid + 1]) right = mid;
        }
        return left;
    }
};

int main()
{
    return 0;
}